In the modern lightning protection technology field, the grounding grid is critical factor to the success of the lightning protection process. The grounding grid is a lightning current discharging network consisting of a main ground lead and several grounding electrodes (grounding bodies). Here, the grounding electrodes are conductors buried underground with one end connecting to the main ground lead and the other end buried underground (connecting to the ground). To illustrate the applications of the grounding grid, a tower for supporting transmission lines is used as example. The tower is generally made of metal material. When the tower is struck by lightning, lightning currents are discharged into the grounding grid, where the currents are transmitted to individual grounding electrodes via the main ground lead, thereby being discharged into the ground via the individual grounding electrodes. The great amount of the electric charges carried by the lightning currents are neutralized with the opposite charges in the ground so as to discharge the lightning currents, which achieves the purpose of lightning protection.
Currently, the grounding grid uses the grounding electrode, which structurally comprises: metal rods and metalloid blocks of definite shape, for example graphite blocks. The metal rod has one end inserted into the graphite block and the other end connecting to the main ground lead of the grounding grid.
Nowadays, the environment of the site where a grounding grid is needed to be setup is generally complex, for example, a rocky area. Hard rocks have the electrical resistivity relatively high and the conductivity performance poor, so it is required that the grounding grid has higher conductivity property However, the grounding electrodes being used in the existing grounding grids are partially metalloid blocks definite shape, which have small contact surface area with the rocks after being buried into the rocks, thereby causing the lightning currents cannot be discharged into the rocks or ground rapidly through the metalloid blocks definite shape. In such cases, electric charges resulted from the lightning currents cannot be neutralized with opposite charges in the ground quickly, so making the discharging effect of lightning currents poor.